As far as his blockstrings go, the main thing you need to keep in mind is how long your opponents normals are. In general, the longer their normals are, the more C normals you want to add to the end of a blockstring before ending with 22A.
So against someone like akatsuki, AB2Cxx22A will usually put you in a position that you can fish for a counterhit with 5BB or 2C and since you have the puddle from the 22A you get a super easy confirm.
On someone like Nanase, though, there are ranges where AB2Cxx22A isn't plus enough so you'll want to add a 5C,3C, and/or 6C before the 22A so you can abuse the range in his normals.
Also, j.[C] seems like it should be one of those buttons you throw out all day, but you want to resist using it on normal jumps because you do have some landing recovery and can get punished of it. Try to get used to poking with j.B (especially jump back j.B, land, 2C when you have a puddle nearby.) That normal has a great hitbox for defensive and offensive okay.
In general, I think his combos actually require a bit of dedication (this coming from someone that plays Magneto and Dante in UMvC3 and is pretty comfortable with higher execution requirements.) For me, the dash 2B pickup took some work (start by practicing it off a 5B or 3C starter.) Also, the cancel timing on uniel is a bit strange compared to other fighters so make sure you're delaying your specials so that the A/B his around the same time the normal your trying to cancel off of is hitting your opponent. On the 5BB (1st hit whiffs)combos, make sure you're starting the combo with the tip of the 5B starter to get the right spacing (those combos are meant specifically for converting off max range pokes.)
Some of his higher damage corner combos are actually pretty high execution, links + timing jump/charge normals to hit at specific heights and juggling off of negative edge traps. I've had a ton of fun with him and I feel like he's easily up there with the big 3, tier-wise, he just takes more dedication and pays much better returns on the effort you put into him.